Book contents
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Discovery
- 3 Basic theory
- 4 Observations of masers
- 5 Maser molecules
- 6 Environments of masers
- 7 Advanced theory
- 8 Computer modelling
- 9 Masers as diagnostics
- 10 Future prospects
- Appendix A Boltzmann's formula
- Appendix B Vector identities
- Appendix C Dirac delta-function
- Appendix D Change of variables in integration
- Appendix E Coordinate systems
- Appendix F Lagrange inversion theorem
- Appendix G Local standard of rest
- Appendix H Stochastic processes
- Appendix I Fourier transforms
- Appendix J Matrices
- Appendix K The centre of mass frame
- Appendix L Quantum-mechanical operators
- References
- Index
10 - Future prospects
Published online by Cambridge University Press: 05 May 2012
- Frontmatter
- Contents
- Preface
- 1 Introduction
- 2 Discovery
- 3 Basic theory
- 4 Observations of masers
- 5 Maser molecules
- 6 Environments of masers
- 7 Advanced theory
- 8 Computer modelling
- 9 Masers as diagnostics
- 10 Future prospects
- Appendix A Boltzmann's formula
- Appendix B Vector identities
- Appendix C Dirac delta-function
- Appendix D Change of variables in integration
- Appendix E Coordinate systems
- Appendix F Lagrange inversion theorem
- Appendix G Local standard of rest
- Appendix H Stochastic processes
- Appendix I Fourier transforms
- Appendix J Matrices
- Appendix K The centre of mass frame
- Appendix L Quantum-mechanical operators
- References
- Index
Summary
At present, there are a number of radio astronomy projects in progress which promise to revolutionize our understanding of astrophysical masers and their environments. Masers form only a small part of the impressive science programmes for these new telescopes, so this chapter contains a considerable amount of general material about the instruments and their capabilities.
EVLA
Introduction to the EVLA
The Expanded Very Large Array (EVLA) is a two-phase development of the existing VLA, situated in New Mexico, USA, and operated by the National Radio Astronomy Observatory. The general capabilities of the EVLA can be found at the website http://www.aoc.nrao.edu/evla/. Phase 1 developments are technological, upgrading the existing array to a wide-band system, whilst Phase 2 involves the construction of new antennas, to provide significantly improved spatial resolution, and improved linkage to the VLBA. The technological developments are similar to those of e-MERLIN (see Section 10.2).
Continuum sensitivity improvements range from a factor of 5 at low frequencies to 20 or more above 10 GHz. This is important for maser, and all spectral line, observations, because the spectral line observations rely on continuum sources for calibration. Spectral line sensitivity increases in Phase 1 are modest below 10 GHz, but up to a factor of 3 at higher frequencies. The EVLA will also move to a wide-band receiver system with fibreoptic cabling and digital electronics, allowing complete frequency coverage from 1 to 50 GHz, with a bandwidth of up to 8 GHz per polarization.
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- Information
- Maser Sources in Astrophysics , pp. 352 - 361Publisher: Cambridge University PressPrint publication year: 2012